Managing Excessive Anticoagulation and Vitamin K Recommendations

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Managing Excessive Anticoagulation and Vitamin K Recommendations

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INR (symptoms) Warfarin Recommendations/Vitamin K dosing

Above therapeutic range

But <5.0

Hold warfarin. When therapeutic, restart at same dose and decrease the dose if INR is greatly above therapeutic range.

5.0-9.0

(-) bleeding

Hold warfarin; recheck INR in 24 hours. If therapeutic, resume therapy at lower dose.

(+) bleeding/risk for bleeds

Hold warfarin; give oral vitamin K 2.5-5 mg. Monitor decrease in INR within 24-48 hours. Resume at lower dose when INR is therapeutic.

Serious bleeding or

warfarin toxicity

Hold warfarin; give vitamin K, 5-10 mg, diluted in 100 mg D5W - IV (slowly <1mg.min). FFP used alternative or in addition. Repeat vitamin K q 12h until desired range is achieved.

Surgery/

dental procedure

Hold warfarin; give vitamin K 2.5 mg po. If INR is still elevated after 24 hours, give additional 2.5 mg orally.

* Intravenous vitamin K should be given slowly (<1 mg/min) because of hypersensitivity danger.

* Vitamin K will reduce the INR in patient with normal LFTs within 4-24 hours.

* Excessive vitamin K (> 25 mg) can make the patient resistant to warfarin for 1-2 weeks.

Management of Nontherapeutic INR's

• For patients with INRs greater than the therapeutic level, but < 5.0 who do not have significant bleeding:

lower the dose or omit a dose and resume therapy at a lower dose when the INR is at the therapeutic level. If the INR is only minimally greater than the therapeutic range, no dose reduction may be required

• For patients with INRs >5.0 but < 9.0 with no significant bleeding:

omit the next one or two doses, monitor the INR more frequently, and resume therapy at a lower dose when the INR is at the therapeutic level. Alternatively, omit the dose and administer vitamin K1 to 2.5 mg orally, particularly if the patient is at increased risk of bleeding. If more rapid reversal is required because the patient requires urgent surgery, administer vitamin K1, 2 to 4 mg orally, with the expectation that a reduction of the INR will occur in 24 h. If the INR is still high, administer an additional dose of vitamin K1, 1 to 2 mg orally

• For patients with INRs > 9.0 with no significant bleeding:

hold off on warfarin therapy and administer a higher dose of vitamin K 1, 3 to 5 mg orally, with the expectation that the INR will be reduced substantially in 24 to 48 h. Monitor the INR more frequently and administer additional vitamin K 1 if necessary.

Resume therapy at a lower dose when the INR reaches the therapeutic level

• For patients with INRs > 20 with serious bleeding:

hold off on warfarin therapy and administer vitamin K1, 10 mg by slow IV infusion, supplemented with fresh plasma or prothrombin complex concentrate, depending on the urgency of the situation. Administration of vitamin K1 can be repeated every 12 h

• For patients with life-threatening bleeding:

hold off on warfarin therapy and administer prothrombin complex concentrate supplemented with vitamin K1, 10 mg by slow IV infusion. Repeat this treatment as necessary depending upon the INR.

Source: 6th ACCP Consensus Conference on Antithrombotic Therapy

As published in CHEST January, 2001 Supplement. Note: All recommendations above are Class 2C (definition: less certain recommendation based upon observational studies or from generalization from randomized trials from one group of patients to a different group; fertile ground for further randomized control studies).